ekohn
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Post by ekohn on Jan 26, 2023 12:23:44 GMT -5
I have a pair of Thiel CS 3.7s, they do need a lot of power, and i do have a very limited budget.
Currently there's an auction for the almost 20 yo Bryson's but am i better off passing on them and getting a a new pair of the XPA-DR1?
Bryson has always been one of the Amps listed to drive thiels. But there may be some risk in these.
If I don't like the Brysons, I'm screwed. I've read some good things about the Emotivas, and if i didn't like them i could return.
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cawgijoe
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"We made too many of the wrong mistakes." - Yogi Berra
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Post by cawgijoe on Jan 26, 2023 13:05:37 GMT -5
I have a pair of Thiel CS 3.7s, they do need a lot of power, and i do have a very limited budget. Currently there's an auction for the almost 20 yo Bryson's but am i better off passing on them and getting a a new pair of the XPA-DR1? Bryson has always been one of the Amps listed to drive thiels. But there may be some risk in these. If I don't like the Brysons, I'm screwed. I've read some good things about the Emotivas, and if i didn't like them i could return. First off I'm very jealous that you have Thiel CS 3.7s! I love my CS 1.6, but would be great to own 3.7s. Bryston makes excellent amps. They have a 20 year warranty. The problem is, if the used Bryston you are looking at is almost twenty years old, you are possible going to run into service issues. Also, I'm unsure whether any remaining warranty can be transferred to a new owner. And, how many owners has that amp had? If the price is cheap and the amp works, and you are willing to repair if needed, it may be worth taking the chance. Personally I would go with a new amp with a good return policy and warranty. The XPA-DR1s should have no problem driving the Thiels. |
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Post by Dan Laufman on Jan 26, 2023 13:21:58 GMT -5
BTW, warranty is non-transferrable on Bryson's... a risky proposition... Transferrable on Emotiva.
The DR's will drive the Thiel's beautifully!
If you don't love them send em' back.
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ekohn
Seeker Of Truth
Posts: 5
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Post by ekohn on Jan 26, 2023 14:48:09 GMT -5
BTW, warranty is non-transferrable on Bryson's... a risky proposition... Transferrable on Emotiva. The DR's will drive the Thiel's beautifully! If you don't love them send em' back. I like hearing everyone get behind the XPA-DR1s! I'm still worried about driving the Thiels, thought they say 4 ohms, charts shows down to 2 a lot. I don't want to argue on the Bryson warrantee, but i did reach out to them with the serial numbers to see if it would TX and for how long. Seems not a problem for the last 2 years. |
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cawgijoe
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"We made too many of the wrong mistakes." - Yogi Berra
Posts: 4,918
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Post by cawgijoe on Jan 26, 2023 14:58:56 GMT -5
BTW, warranty is non-transferrable on Bryson's... a risky proposition... Transferrable on Emotiva. The DR's will drive the Thiel's beautifully! If you don't love them send em' back. I like hearing everyone get behind the XPA-DR1s! I'm still worried about driving the Thiels, thought they say 4 ohms, charts shows down to 2 a lot. I don't want to argue on the Bryson warrantee, but i did reach out to them with the serial numbers to see if it would TX and for how long. Seems not a problem for the last 2 years. I'm using an XPA-5 Gen 3 with my Thiel CS 1.6 with no issue and great results. They also are 4ohm and can drop to 2ohm. |
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Post by tropicallutefisk on Jan 27, 2023 6:36:44 GMT -5
I have a pair of Maggie 3.7is, another speaker considered to be "difficult" to drive. I'm not sure that's what I'd say, but they are 4 ohm and low sensitivity. I've used lower powered McIntosh and Rotel amps with them, and they sounded "good". However, when I hooked them up to a pair of DR-1s that's the first time I really heard them sing. I'm sure there are plenty of people with plenty of other opinions, but I in my experience the DR1 has been an excellent choice for my system and I consider them a great value.
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Post by leonski on May 6, 2023 1:45:03 GMT -5
I have a pair of Maggie 3.7is, another speaker considered to be "difficult" to drive. I'm not sure that's what I'd say, but they are 4 ohm and low sensitivity. I've used lower powered McIntosh and Rotel amps with them, and they sounded "good". However, when I hooked them up to a pair of DR-1s that's the first time I really heard them sing. I'm sure there are plenty of people with plenty of other opinions, but I in my experience the DR1 has been an excellent choice for my system and I consider them a great value. With all due respect, Tropic? Maggies are not a 'difficult' speaker to drive. What they are is VERY low sensitivity which means lots of power. But I've see tubes AND transistor gear work well with 'em. Nearly ANY amp which will sink enough power will work.....some better than others. A buddy of mine has 20's and has them biamped. Emo on the bottom and some tube amp on top....with I think a Marchand crossover..... But electrically? No where near as bad as many Thiel speakers which can have large impedance and reactance swings.... I'd personally LOVE some of the now vintage (sort of) 3.6s to modify / improve. I've owned Magnepan for maybe almost 40 years...... My Experience with a Rotel RB-1070 and MG1.6 was awful.... |
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Post by vcautokid on May 6, 2023 4:25:55 GMT -5
I sold Rotel for years. The RB-1070 and 1080 in the right match with the speaker is excellent. The RB-1090 which is insane money now hits very well. Again out of warranty, you pays your money, you takes your chances. What is it going to need. At least a recapping, needs to be rebiased and so on. Buy new with warranty needs nothing. Except your favorite music, and or movies. The risk with used. What are you prepared to deal with. Are you a nut like me messing with stuff from the 70s?
Or do you like that nice brand new no worries process. Bryston is fine, heck they might even accommodate you. They might not. Risk right?
You got nothing to lose trying the DR or any Emotiva product. Depends what you want to do. A man got to know his expectations.
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Post by leonski on May 6, 2023 22:19:47 GMT -5
Vac.....I THINK if I had nutted up and bought the RB1080 with 200x2 @8 for my panels, I'd have been happy.
Even THIS amp has only 4ohm minimum listed at speaker terminals and NO 4ohm rating......or bridged mono, for that matter.
As it was? RB1070 was 335 MONO Bridged / 8 ohms....which implies about 165 4 ohm watts against rated 130 @8......
NO 4ohm factory rating. NONE....
It just couldn't cut it with my 4 ohm panels. Totally insufficient PS, even if the output side could have withstood it.
Music was flat and uninvolving. Turning up sure didn't help.
Replaced with a 'D' amp....using B&O ASP modules of 250x2 which was FINE.....but ultimately also unsatisfying but for other reasons.....
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Post by Boomzilla on May 6, 2023 22:51:07 GMT -5
I’ve owned a couple of Brystons, and honestly - although they were super well built, their sound didn’t wow me that much. I also owned a huge McIntosh that I thought sounded notably superior to the Bryston’s. Can I describe that “better?” It would be subtle, but the Mac had a quieter-sounding background.
Emotiva, Rotel, Odyssey, and others offer powerful, new amps with warranties. But allow me to deal you a wild card…. Pro power amps offer 2-Ohm current ratings, massive power for the $$, and super durability. Some don’t sound very good, but some do. You can’t predict sonic quality by brand, model, or power rating either. You have to experiment until you hit a winner. My audio amigo runs his Thiel 5i speakers with an old Crown PSA - it sounds amazing!
Happy shopping - Boomzilla
Postscriptum - When shopping for pro amps, one way to get the best possible sound quality is to studiously avoid any power amp that has DSP (digital signal processing) functions. If the amplifier has built in high or low pass filters, or if it is advertised as having sound shaping technology it probably won't sound very good. Why? Every time you change a signal from analog to digital and back again, you damage the music. Plus, the Analog-to-Digital and Digital-to-Analog chips in pro amps are the cheapest they can get.
Note that pro amps all have analog inputs. Therefore, to apply digital processing, the incoming analog signal must be converted to digital and then processed. When processing is complete, the signal must be converted back to analog to feed the amplification modules. The result (virtually always) is a glassy sound that can easily be bettered. Note also that amps with DSP do not normally allow you to bypass the DSP sections.
Again - happy shopping!
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Post by leonski on May 7, 2023 16:27:10 GMT -5
I have the Parts Express amp in my garage. PERFECT and plays as loud as I wish with speakers that came with an experimental surrround sound setup. Amp was 35$ to my door.....I'd guess no more than 5 or 6 watts a side. It'll take 8X AA batteries if I want to 'go portable'......A pair of Minimus 7, this amp, and my phone as source for backpacking or car camping......  ? Power Ratings of those 'pro' amps are mostly bogus. NONE will, I suspect, pass the FTC criteria. Even my old ASP modules from B&O were TIME LIMITED at power rating and the FTC rating was FAR lower.....something they do NOT tell you on the 'big power' brag advertising... If I wanted to experiment with DSP? I'd get the MiniDSP and setup for active biamp......Than be forced to figure out FIR filters..... |
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Post by Boomzilla on May 7, 2023 22:05:40 GMT -5
...Power Ratings of those 'pro' amps are mostly bogus. NONE will, I suspect, pass the FTC criteria... I must politely disagree. Pro amps live and die by their power output - by their low impedance tolerance - and by their durability (including getting wet in the rain and inadvertent dead shorts). Pro musicians won't pay for amps that don't meet their specs. In fact, I'd contend that pro amps, more than home ones, DO meet their published specs. |
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Post by leonski on May 8, 2023 1:12:05 GMT -5
Go to page 6 or 7 of the 'datasheet' and you tell ME. FTC for the mid-module of the 3 is 200 watts....up to 3khz. After that? You'll tend to cook the Zobel. Plug to speaker efficiency IS very high at around 80%......or maybe a tick higher. That means that 20% is HEAT at the highest powers. In the 'curves' section of the datasheet, you'll see Damping factor drops into the mud at higher frequencies.....and frequency response drops off a cliff much past 20khz...depending on impedance. What this means is the Zobel is doing its job. But that huge frequency drop is ALSO phase shift which can have audible effects. Time Limits apply, too. I looked at Crutchfield at a Yamaha 'pro' amp. Very high power, to be sure AND if it will drive the claimed 1 ohm? Bring on the Apogee Speakers. icepoweraudio.com/buy/asp-series/500asp/Please read this datasheet. You may say that 'progress' has been made in 'D' amps, but you are still limited by Bridge or Half Bridge topology along with essential limits in the physics of efficiency. I think somewhere they may specify 15 seconds or 30 seconds.....MAYBE 1 minute.....at full power before thermal shut down..... The KEY to what I said is FTC. Does Anyone stress an amp in this fashion? I tend to doubt it. In my couple years with my 'D' amp, i was only able to get the top cover slightly warm. And that was into power hungry Magnepan. But if you had caught me 35 years ago when a bachelor? It might have been a different story. BTW? Overall I liked my PSAudio GCC amp. It just proved audibly unsatisfying in the long run. I much prefer my slightly hi-bias Parasound Halo amps......one per speaker....which STILL have less total claimed power than the 'D' amp they replaced. And will play as loud or louder.... Don't let my disrespect for the SPECS of most 'D' and pro amps disturb you. If I wanted PRO amps? I'd be tempted to go with Bryston. |
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Post by Boomzilla on May 8, 2023 9:36:03 GMT -5
Well, I wasn’t specifically talking Class-D amplifiers…. There are plenty of AB pro amps left, and, in fact, the Crown PSA that my audio amigo uses on his Thiels is an AB.
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Post by leonski on May 8, 2023 13:20:43 GMT -5
Well, I wasn’t specifically talking Class-D amplifiers…. There are plenty of AB pro amps left, and, in fact, the Crown PSA that my audio amigo uses on his Thiels is an AB. Color me surprised. I'd thought 'D' had taken over completely! or 'T' which was around for a while and may still be. Still and all, if A/B? Than I must default to weight. An amp weighs 20lb with an output of 300 watts? I'd have to say 'too light' since for that output, maybe 1/2 the power is Heat. And if 'A'? Even heavier! Maybe 1lb per watt to start... I'd listen to some of these amps. But, as you say, I'm also suspicious of DSP where A-D than D-A conversions are done in the amp. And who knows just WHAT the 'P' part of DSP actually is. Pro users who setup in different spaces may actually NEED such features even at the expense of perfect sound. |
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Post by Boomzilla on May 8, 2023 15:30:50 GMT -5
Any 20lb amplifier that supposedly puts out 300wpc IS a Class-D amp. The power supply capacitors alone for an AB 300wpc amplifier weigh more than 20 pounds, not to mention the transformer...
That said, the majority of current "pro" amplifiers ARE Class-D. The cool operating temperatures, lower power consumption, and lighter weight are all advantages for an amp that must be moved from place to place.
There are not now, and never have been ANY Class-A "pro" amplifiers. That amplifier configuration is unique to home audio.
All that said, if you can find Class-D pro amplifiers without DSP (or with completely bypassable DSP), then they can sound anywhere from pretty good to really good. I'm currently using a pair of Emotiva Class-D amps built on B&O ICE modules (the Emotiva PA1 units) and find them really, really good once warmed up! In fact, the PA1 amps are within spitting distance of the Emotiva XPA1, generation 2 amplifiers (some of the very best ever from Emotiva).
Boom
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KeithL
Administrator 
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Post by KeithL on May 8, 2023 16:35:32 GMT -5
1. "Tripath" amps were just another variant of Class-D. They were quite nice, but arguably nothing special, and as far as I know Cirrus Logic bought the "technology". 2. With a Class A/B amp the maximum efficiency is around 70% into the impedance they're optimized for. (So an amp rated for an 8 Ohm load is probably 70% efficient into 8 Ohms and 50% into 4 Ohms.) However, as Leonski noted, the limitation on size and weight is strictly related to heat dissipation. This is especially true if you use a switch mode power supply and avoid the big heavy transformer. So, in fact, you could EASILY design a 300 WPC Class A/B amp that weighed 20 pounds. But, without heavy heat sinks, it would need a big nasty-ass fan to get rid of all the heat... which many pro amps do indeed have. (There are fancy computer graphics cards that generate more heat than a 600 watt Class A/B amp would.) 3. The question of "DSP" in amps can be an interesting one. I entirely agree that adding DSP processing to a Class A/B amplifier adds a lot of needless complexity, and needless conversions... However, if you have a Class-D amp already, that distinction is somewhat less clear. Some Class-D designs more or less directly use the analog signal to gate the digital portion of the circuitry... But it would be easy to envision a Class-D amplifier which would accept a digital input directly. We tend to "live in our assumptions". Imagine if your source is a CD, or a digital audio file, or a digital audio stream... (which is often the case these days). And it has a digital audio output... In that case, if you have a Class-D amplifier, then the fewest conversions would be achieved by never converting the signal into analog at all... (There's no reason to add a D/A at the source, and then an A/D on the amp.) (But you could put a DSP processor between them without having to perform ANY conversions.) (And, if you need a Volume control, or even Tone controls, those can all be implemented "perfectly" as DSP functions.) Well, I wasn’t specifically talking Class-D amplifiers…. There are plenty of AB pro amps left, and, in fact, the Crown PSA that my audio amigo uses on his Thiels is an AB. Color me surprised. I'd thought 'D' had taken over completely! or 'T' which was around for a while and may still be. Still and all, if A/B? Than I must default to weight. An amp weighs 20lb with an output of 300 watts? I'd have to say 'too light' since for that output, maybe 1/2 the power is Heat. And if 'A'? Even heavier! Maybe 1lb per watt to start... I'd listen to some of these amps. But, as you say, I'm also suspicious of DSP where A-D than D-A conversions are done in the amp. And who knows just WHAT the 'P' part of DSP actually is. Pro users who setup in different spaces may actually NEED such features even at the expense of perfect sound. |
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Post by Boomzilla on May 8, 2023 18:26:42 GMT -5
...Imagine if your source is a CD, or a digital audio file, or a digital audio stream... (which is often the case these days). And it has a digital audio output... In that case, if you have a Class-D amplifier, then the fewest conversions would be achieved by never converting the signal into analog at all... (There's no reason to add a D/A at the source, and then an A/D on the amp.) (But you could put a DSP processor between them without having to perform ANY conversions.) (And, if you need a Volume control, or even Tone controls, those can all be implemented "perfectly" as DSP functions.) ... The word of note above is "could." Yes, a totally digital signal path is possible, but offhand I know of no pro amplifier manufacturer who has one - I'm not saying it doesn't exist, just that I haven't stumbled across any yet. All the pro amps I've seen use analog XLR inputs. But having an all digital signal path would be cleaner, by far! |
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Post by leonski on May 8, 2023 20:55:00 GMT -5
I'd say POTENTIALLY cleaner. But some amps these days are well over 105 to 110 db SNR that 'better' in that regard is nutty.
As for some of the other distortions? Arent' we nearly up against human limits of perception?
I'd love to audition a TOTALLY and REALLY digital amp from input to speaker outs.....
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Post by leonski on May 9, 2023 0:31:20 GMT -5
1. "Tripath" amps were just another variant of Class-D. They were quite nice, but arguably nothing special, and as far as I know Cirrus Logic bought the "technology". 2. With a Class A/B amp the maximum efficiency is around 70% into the impedance they're optimized for. (So an amp rated for an 8 Ohm load is probably 70% efficient into 8 Ohms and 50% into 4 Ohms.) However, as Leonski noted, the limitation on size and weight is strictly related to heat dissipation. This is especially true if you use a switch mode power supply and avoid the big heavy transformer. So, in fact, you could EASILY design a 300 WPC Class A/B amp that weighed 20 pounds. But, without heavy heat sinks, it would need a big nasty-ass fan to get rid of all the heat... which many pro amps do indeed have. (There are fancy computer graphics cards that generate more heat than a 600 watt Class A/B amp would.) 3. The question of "DSP" in amps can be an interesting one. I entirely agree that adding DSP processing to a Class A/B amplifier adds a lot of needless complexity, and needless conversions... However, if you have a Class-D amp already, that distinction is somewhat less clear. Some Class-D designs more or less directly use the analog signal to gate the digital portion of the circuitry... But it would be easy to envision a Class-D amplifier which would accept a digital input directly. We tend to "live in our assumptions". Imagine if your source is a CD, or a digital audio file, or a digital audio stream... (which is often the case these days). And it has a digital audio output... In that case, if you have a Class-D amplifier, then the fewest conversions would be achieved by never converting the signal into analog at all... (There's no reason to add a D/A at the source, and then an A/D on the amp.) (But you could put a DSP processor between them without having to perform ANY conversions.) (And, if you need a Volume control, or even Tone controls, those can all be implemented "perfectly" as DSP functions.) Color me surprised. I'd thought 'D' had taken over completely! or 'T' which was around for a while and may still be. Still and all, if A/B? Than I must default to weight. An amp weighs 20lb with an output of 300 watts? I'd have to say 'too light' since for that output, maybe 1/2 the power is Heat. And if 'A'? Even heavier! Maybe 1lb per watt to start... I'd listen to some of these amps. But, as you say, I'm also suspicious of DSP where A-D than D-A conversions are done in the amp. And who knows just WHAT the 'P' part of DSP actually is. Pro users who setup in different spaces may actually NEED such features even at the expense of perfect sound. 300 watts TOTAL @70% is still nearly 100 wasted watts....used to warm your room. At the more reasonable 50%? 150 watts WILL put a dent in the AC bill. I suspect (know) the efficiency is lower at lower powers. FTC calls for a preconditoning period at some fraction of 'rated' power which stereophile calls 'worst case scenario'.....Some amps either fail this or are cooking hot. The 'D' amp I reference is 'only' 9 watts, at ZERO output, the so-called housekeeping power. And therefore ZERO efficiency. At maybe a total of 9 watts output, which is useable for more sensitive speakers, you are up to a robust 50%, unless housekeeping power also rises to some unknown degree. PS is nice but not THAT big a player.....The output topology / bias is what drives most of this...... I've seen heat sink calculator and it REALLY adds up. I went thru hell when I build my own PCs with getting the best CPU heat sink. And I'd take it apart periodically and De-Dust. My last PC had something like 7 or 8 fans, counting the PS, the CPU and multiple CASE fans. Some blowing IN and were filtered. Lian Li makes on heck of a case. |
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